* Removed div.terminal_bg whose purpose was to hold the background SVG, as this div was occluding the scrollbar, and instead set SVG as the background-image of div.terminal_container using CSS.
* As CSS does not have a background-opacity directive, manually decoded, edited and re-encoded the SVGs (light, dark) so that all <g>s are wrapped in a top-level <g opacity="0.1">
* Improved the rules of how the background image resizes